This was kinda a problem with the 3.5 psion as well. The issue was since psionics overall were considered an add-on and not part of the base game, the DM had to consciously add them for the psionic character and it seemed to stand out. Enemy starts using psionics? This fight is for Bob. Found a psionic item? Here you go Bob. Running a module? Better swap in or add some psionic monsters or items for Bob. The problem is even more pronounced the more additional systems you add on: running a game with psionics, magic, incarnum and martial maneuvers would mean everyone is their own little island.